The objectives for this work are to develop methods which can be effectively used to alter the leukemic process. We are developing methods of early biochemical diagnosis of acute lymphoblastic leukemia by use of chemical markers present in proliferating cells. One such marker of special interest to us is taurine, an acidic biogenic amine. We are investgating the role or roles of taurine, and its precursors, in the control of cellular proliferation in normal as well as leukemic cells. We are studying several aspects of these compounds: 1) whether the intracellular concentration of these compounds can be used to gauge the proliferative state of the leukemic process or its maturation; 2) whether changes in taurine concentration, within the cell, during the course of experimental manipulation, will relate, in any way, to tumor volume and/or proliferative capacity; 3) whether known specific agents which alter taurine metabolism might alter the leukemic process or cellular proliferation as well.